| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "include/ese/ese.h" |
| |
| static inline uint32_t min_u32(uint32_t a, uint32_t b) { return a < b ? a : b; } |
| |
| ESE_API uint32_t ese_sg_length(const struct EseSgBuffer *bufs, uint32_t cnt) { |
| const struct EseSgBuffer *buf = bufs; |
| uint32_t len = 0; |
| if (!bufs || cnt == 0) { |
| return 0; |
| } |
| while (buf < bufs + cnt) { |
| /* In reality, this is probably corruption or a mistake. */ |
| if (ESE_UINT32_MAX - len < buf->len) { |
| return ESE_UINT32_MAX; |
| } |
| len += buf->len; |
| buf++; |
| } |
| return len; |
| } |
| |
| ESE_API uint32_t ese_sg_to_buf(const struct EseSgBuffer *src, uint32_t src_cnt, |
| uint32_t start_at, uint32_t length, |
| uint8_t *dst) { |
| const struct EseSgBuffer *buf = src; |
| uint32_t remaining = length; |
| if (!src || src_cnt == 0) { |
| return 0; |
| } |
| while (remaining && buf < src + src_cnt) { |
| if (start_at > buf->len) { |
| start_at -= buf->len; |
| buf++; |
| continue; |
| } |
| uint32_t copy_len = min_u32(remaining, buf->len - start_at); |
| ese_memcpy(dst, buf->c_base + start_at, copy_len); |
| dst += copy_len; |
| remaining -= copy_len; |
| start_at = 0; |
| buf++; |
| } |
| return length - remaining; |
| } |
| |
| ESE_API uint32_t ese_sg_from_buf(struct EseSgBuffer *dst, uint32_t dst_cnt, |
| uint32_t start_at, uint32_t length, |
| const uint8_t *src) { |
| const struct EseSgBuffer *buf = dst; |
| uint32_t remaining = length; |
| if (!dst || dst_cnt == 0) { |
| return 0; |
| } |
| |
| while (remaining && buf < dst + dst_cnt) { |
| if (start_at >= buf->len) { |
| start_at -= buf->len; |
| buf++; |
| continue; |
| } |
| uint32_t copy_len = min_u32(remaining, buf->len - start_at); |
| ese_memcpy(buf->base + start_at, src, copy_len); |
| src += copy_len; |
| remaining -= copy_len; |
| start_at = 0; |
| buf++; |
| } |
| return length - remaining; |
| } |